The present embodiments relate to a stand for holding a radiation detector for a radiation therapy device.
Radiation therapy devices are used in medicine to treat diseased tissue, such as tumor tissue, with ionizing radiation. During radiation therapy, radiation is used. The radiation may be, for example, high-energy X-ray radiation, radiation composed of lightweight particles, such as electrons or positrons, or radiation composed of heavy particles, such as protons or ions. During radiation therapy, it is desired that only the diseased tissue is specifically bombarded, while the surrounding, healthy tissue is mostly not irradiated.
The respective treatment area is positioned as exactly as possible relative to the radiation therapy device in order to only irradiate the diseased tissue. The radiation is aligned and delineated as exactly as possible with respect to the irradiation area. A radiation detector, which uses the therapeutic radiation to produce an image of the irradiation area or its surrounding area, may be used for positioning of the treatment area and for alignment and delineation of the therapeutic radiation. Because of its high quantum energy, the therapeutic radiation is scattered to a greater extent about the treatment area and the tissue surrounding this treatment area than diagnostic radiation, whose quantum energy is lower, so that this type of imaging has comparatively low contrast. Diagnostic X-ray radiation may have a maximum quantum energy of 150 kiloelectron volts (KeV) while, in contrast, therapeutic X-ray radiation typically has a quantum energy in the region of a megaelectron volt (MeV).
U.S. Pat. No. 6,888,919 B2 discloses an additional, diagnostic X-ray imaging system that is used for exact positioning of the tumor. The X-ray imaging system includes an X-ray source for production of low-energy diagnostic X-ray radiation and a radiation detector for diagnostic imaging based on detection of the diagnostic X-ray radiation. U.S. Pat. No. 6,888,919 B2 also discloses a radiation therapy device in which the therapeutic radiation source is arranged on a gantry that can be rotated around a horizontal axis in order to allow the therapeutic radiation to be aligned flexibly relative to the patient.
In order to allow the diseased tissue to be positioned as freely as possible, the gantry and the components arranged on this gantry are compact. The distance from the radiation head to the isocenter of the radiation therapy device should be as great as possible. The radiation head may include the therapeutic radiation source and at least one collimator for beamforming. Particularly in the case of radiation therapy devices with an additional diagnostic X-ray imaging system, the lack of space represents a major problem for the design configuration of the radiation therapy device.
U.S. Pat. No. 6,888,919 B2 discloses a radiation therapy device. The radiation therapy device includes a first and second gantry. The first gantry can be rotated about an axis and has a therapeutic radiation source. The second gantry can be rotated about the same axis and has a diagnostic radiation source on one side and a radiation detector for imaging on the other side. The radiation detector is a multi-energy imaging unit that can produce an image both on the basis of the therapeutic radiation and on the basis of the diagnostic radiation. The diagnostic X-ray emitter may be moved in and out. To produce an image based on the diagnostic X-ray radiation, the first gantry is pivoted with the therapeutic radiation source to the side with respect to the second gantry with the diagnostic radiation source, so that the diagnostic radiation source can be moved out. To treat the diseased tissue with the therapeutic radiation, the diagnostic X-ray radiation source is moved in, and the therapeutic X-ray radiation source together with the gantry is pivoted to the previous position of the moved-out, diagnostic X-ray radiation source. A diagnostic image of the diseased tissue is produced first with the moved-out diagnostic X-ray radiation source, from a viewing angle that corresponds to the radiation direction of the subsequent radiation treatment using the therapeutic radiation source. The free space for positioning and alignment of the patient to be treated is restricted because of the additional second gantry. The radiation therapy device design is complicated.